First Time Bathroom Remodel - Adding a tub

Hey all. Been lurking these boards for a good while now, and am now preparing to take on my first DIY project (painting and the like aside).

Our master bathroom has bothered me to no end in the year and a half that we've owned the house.

We do not have a bathtub, but rather a large drop-in shower. I personally don't care (not a big bath guy), but my wife is dying for a tub.

I have a neighbor who has done a bunch of work on his own house is going to be helping me with this project (except plumbing, getting someone with insurance to do that bit ). I wanted to get as much planning done as possible before hand, though, and am in a bit of a muddle.

The niche where the shower currently is 59" x 36" with a wall separating the shower from the toilet, which rules out that large soaking tub that my wife wanted. Doing a bit of looking into tub sizes and whatnot, I've discovered that that being one inch shy of 5 feet is going to cost us about a foot of tub length.

Barring getting a tiny tub, how much of a hole would a beginner (with help from someone with moderate experience) be digging himself into in moving that wall to accomodate a larger tub? My intial concern is making the toilet's niche claustrophobic.

I'm considering having a consultant come and look at my bathroom and just give me alternate options, but thought I'd bounce it off you folks first.